Since 1947 Highly Absorbable Calcium Citrate Form Promotes Healthy Bones Supports Nerve & Muscle Function Non-GMO Gluten, Wheat & Dairy Free Certified Gluten-Free Kosher Parve Dietary Supplement Calcium provides the building blocks that help keep bones and teeth strong and healthy. It also supports the health of the musculoskeletal and nervous systems. Magnesium helps to regulate calcium transport and stimulates the secretion of calcitonin, a hormone that aids in the influx of calcium into bone. Vitamin D is required to promote calcium absorption, which helps to maintain healthy bones and teeth. Vitamin D also supports a healthy immune system. This formulation provides Vitamin D3 for daily supplementation Adequate Calcium and Vitamin D as part of a healthful diet, along with physical activity, may reduce the risk of osteoporosis in later life.